It's definitely not a dead language – a new Fortran front-end has recently been accepted into the LLVM project, joining Clang. So LLVM's only in-tree supported languages (excluding the various IRs) will be C, C++, Objective-C, and Fortran. It had been scheduled for merge into the LLVM monorepo 2 days ago, but has been delayed pending some additional architecture review.
Install numpy, it will pull in Fortran stuff.